In recent years, electronic devices having an electronic book function have been in practical use. Such electronic devices include, for example, an electronic book reader. Also, there have been developed dedicated electronic book readers in the form of a mobile device. Further, the electronic book reader applications that are used by being installed on a mobile device such as a tablet personal computer (PC) and a smartphone have been sold.
When reading an electronic book with such an electronic book reader on a vehicle such as a train or a bus during commuting, it is preferable that the user can operate the reader easily since they have baggage or are holding on to a strap. Page turning is performed most frequently among the operations of an electronic book reader. Conventionally, page turning has been performed by operating buttons such as previous-page or next-page buttons.
With conventional devices, since the displayed page is turned page-by-page with a button operation, it is difficult to efficiently find a desired page by flipping through pages as in a printed book.
Such a problem similarly occurs not only with an electronic book reader but also with page-turning function is incorporated into a PC that displays a document, a table, a picture and web contents (hereinafter generally referred to as a document).